Refractory support



Dec. 6, 1966 M. F. ADAMS ETAL 3,289,372

REFRACTORY SUPPORT Filed Oct. 2, 1963 5 Sheets-Sheet 1 1 NVENTOR5 AIM/PK A 404/145 ,5 mg. MAX A/VFFA/(EA WM &%

5|: 6 195 F. ADAMS ETAL REFRACTORY SUPPORT I5 Sheets-$heet 5 Filed Oct. 2. 1963 United States Patent @fiice 3,289,372 Patented Dec. 6, 1966 3,289,372 REFRACTORY SUPPORT Mark F. Adams and Ethan Max Huffaker, Pullman,

Wash., assignors to Harbison-Walker Refractories Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 2, 1963, Ser. No. 313,326 6 Claims. (Cl. 52--346) This invention relates to refractory supports and, more particularly, it concerns apparatus for supporting a monolithic refractory lining on a supporting wall structure of metal or other structural material having a different coefficient of expansion than the refractory.

The conventional technique employed to support monolithic refractory linings in furnaces, for example, to a structural steel framework, has been to employ refractory hangers suitably shaped to effect a mechanical interlock with the monolithic material. The refractory hanger is, in turn, engaged. by a metal anchor designed to be secured to the steel support. Because of the difference in coefficients of thermal expansion between the refractory material and the steel support, the connection of the monolithic refractory and the metal support has usually involved provision for some degree of relative movement between the refractory and the metal. In some applications, the refractory hanger extends throughout the monolithic lining, whereas the metal anchor extends out of the refractory and slidably engages the steel support. In other situations, the anchor is embedded completely in the monolithic refractory and designed so that the relative movement between the refractory and. the support is accommodated by flexibility of the metal anchor. While such anchoring techniques have been satisfactory for monolithic linings of several inches in thickness (e.g., 9"), where the refractory lining itself develops adequate strength to overcome resistance of the anchorage means to relative movements between the lining and the metal support, they are not as effective for thin monolithic refractory linings of the order of 2" or less. Where such thin linings or coatings are used, the refractory material must be provided with substantially complete reinforcement and support so that conventional anchorage techniques become ineffective from a practical standpoint. Moreover, because of the inherent structural weakness of refractory material in thin layers, it is important that stresses therein as a result of differential expansion between the refractory and the support, be kept to an absolute minimum. Although conventional refractory supporting techniques afford some measure of such relative movement, they do not approach complete elimination of stresses in the refractory.

Accordingly, an object of this invention is to provide an improved refractory support, by which the problems previously incurred in supporting a monolithic refractory lining on a metal wall are effectively and substantially overcome.

Another object of this invention is to provide a monolithic refractory support which is inexpensively formed, and which affords full relative expansive movement between the refractory and a metal backup plate having different thermal expansion characteristics, without stressing the refractory material.

A further object of this invention is to provide a refractory support of the type referred to, by which a monolithic refractory lining may be expeditiously applied to a metal supporting plate without danger of fouling the track system by which substantially complete movement, clue to relative expansion between the refractory and. the metal plate, is permitted.

Still other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a fragmentary elevation showing the track system forming a part of the presentinvention;

FIG. 2 is an enlarged fragmentary perspective view exploded to show the components of the supporting apparatus of this invention;

FIG. 3 is an enlarged fragmentary cross section taken on line 3-3 of FIG. 3, with the addition of the refractory material in place;

, FIG. 3A is a fragmentary cross section taken on line A-A of FIG. 3;

FIG. 4 is a fragmentary cross section taken on line 4-4 of FIG. 3; and

FIG. 5 is an enlarged fragmentary exploded. perspective view of a modified version of the supporting apparatus of the invention.

According to the present invention, a relatively thin refractory lining or coating is supportable on a metal wall having a different coefficient of thermal expansion than the refractory, by applying the refractory to .a grillework such as metal lath, which is, in turn, anchored to a track system capable of affording expansive movement in all directions. The track system is completely and effectively separated from the refractory so that substantially complete relative movement between the refractory and the metal sheet, due to different rates of expansion upon heating, is afforded, without in any way stressing the refractory. The system involves a series of primary tracks fixable to the metal support wall, and. a series of secondary tracks supported on the primary tracks, to afford expansive movement in one component: of direction; while the secondary tracks support slide elements to accommodate expansive movement in another component of direction, thereby permitting universal movement in a plane parallel to both the refractory and the support wall. The slide elements, in turn, are connected to the metal lath ultimately embedded in the refractory coating applied by troweling or gunniting, as desired.

Referring now to the drawings, a metal backup or support Wall is designated by the reference numeral 10. The apparatus by which a monolithic refractory lining 12 is adapted to be connected to the metal wall 10, in a manner so as to compensate for differences of coefficients of thermal expansion between the metal and the refractory lining, is shown to include a plurality of primary tracks 14 welded, bolted, or otherwise suitably fixed to the metal support 10, so as to extend in generally parallel directions. Preferably, the primary tracks 14 extend horizontally where the support wall 10 is vertically disposed; and each is of generally T-shaped cross-section, to define a pair of later-ally projecting flanges 16 spaced from the backup plate 10 to which the primary tracks are fixed. A plurality of similarly parallel secondary tracks 18 are arranged to overlie the primary tracks 14, and extend in a direction to intersect directions in which the primary tracks extend. Hence, in the application of the connecting means of the present invention to a vertical wall, the secondary tracks 18 would extend generally perpendicularly to the tracks 14 or along generally vertical paths. The cross-sectional configuration of the secondary tracks 18 is substantially identical to that of the primary tracks 14, or T-shaped to define a base 20 and a pair of laterally projecting flanges 22. The secondary tracks are supported on the primary tracks for thermally expansive sliding movement along the length thereof by slide elements 24 of generally C-shaped cross-sectional configuration. The backs of the elements 24 are welded or otherwise suitably secured 'to the bases 20 of the secondary tracks; whereas, the forward faces thereof, each generally complementing the shape presented by the flanges 16 on the primary tracks 14, make sliding engagement with the primary tracks, as shown most clearly in FIG. 4 of the drawings. Thus, it will be seen that the secondary tracks are anchored against movement in substantially all directions, except along the length of the primary tracks 14.

A second component of movement, relative to the primary tracks 14 and, thus, the metal backup wall 10, is afforded by slide elements 26. The slide elements are, also, of generally C-shaped cross-sectional configuration, so as to partially envelop and, thus, become secured to the flanges 22 on the secondary tracks 18. Thus, the slide elements, though anchored against movement outwardly and transversely of the second tracks 22, will be free to expansively slide along the lengths of the secondary tracks 18. Projecting from the backs of the slide elements 26, at spaced intervals, are a plurality of integral or stamped-out clips 28, for engagement of an open grillework or metal lath 30 to which the refractory lining 12 is applied in a manner to be described more fully hereinafter. While the grillework 30 is shown to be a continuous piece, it should be understood that small individual sections may be substituted therefor. Also, other keying means may be employed.

To isolate, effectively, the refractory layer 12 from the primary and secondary tracks 14 and 18, respectively, a fluid impervious film 32 is positioned between the metal lath 30 and the remainder of the track assembly including the slide elements 26. As a further measure of protection of insurance against fouling of the tracks, a plurality of channel-shaped track guards 34 are arranged to be placed over the primary tracks 14 and the plastic film 32. As shown in FIG. 3, the track guards are of a length somewhat less than the intended distance between the secondary tracks 18, and envelop that portion of the primary tracks 14 between the points at which the secondary tracks are attached by the slide elements 24. Also, the guards 34 are of a width somewhat greater than the projection of flanges 16, to allow expansive movement in the vertical direction. This is more clearly illustrated in FIG. 3A. Further, if the wall is to be employed in a ceiling construction, it is desirable to loosely secure the guard 34 in place Without detracting from the components of expansive movement of slide elements 24 and 26. Referring to FIG. 3A, the guard 34 may be loosely secured in place by means of bolt 35 and nut 37. Grooves (not shown) may be provided in guard 34, where the bolt 35 passes therethrough, to allow expansive movement in any direction. Other means may be employed of securing guard 34 until the monolithic material is applied, such as, for example, hooks, clips, wire, and crimping.

In use, the primary tracks are first fixed to the metal backup plate, in the manner described above, and the secondary tracks 18 assembled thereto by sliding the elements 24 over the ends of the primary tracks 14. In some instances, it may be desirable to assemble the secondary tracks to the primary tracks before the primary tracks are fixed to the metal backup, so that proper spacing of the primary tracks on the metal backup wall 10 is assured. After the slide elements 26 have been engaged over the flanges 22 of the secondary tracks 20, impervious plastic film 32 is laid over the entire track assembly in a loose condition, so that it may be adapted to the somewhat irregular contour of the tracks. Then, the track guard channels 34 are placed against the metal wall over the plastic film to the position shown in FIGS. 3 and 4 of the drawings. As the plastic film 32 is applied, it will be understood. that the clips 28 on the slide elements 26 will pierce and project through the plastic film. Such rupturing of the plastic film will be of no harmful effect, since the shape of the slide elements themselves affords a measure of protection at the points of rupture. After the metal lath 30 is placed over the assembly and secured by the clips 28, the refractory lining 12 is applied to the metal lath. While various types of refractory material may be employed, and while various techniques of applying the refractory material may be used, it is preferred that the refractory material be of the monolithic ramming or castable type well known to those skilled in the refractory art, so that it may be gunnited or troweled into the metal lath 30. Also, while the thickness of the refractory will vary in different applications and. may be applied in thicknesses of up to one or two inches without exceeding practical limits, the connecting system of the present invention has been found extremely satisfactory where three-quarter inches of castable refractory were gunnited onto the metal lath, and hand troweled to polish and seal any possible open pores as a result of the gunniting operation. Such thin layers of monolithic refractory are possible with the connecting apparatus of the present invention, because the refractory is afforded structural support throughout by the metal lath 30, yet is free to move, by thermal expansion, in all directions relative to the metal wall 10 by virtue of the perpendicular components of direction afforded by the mounting of the secondary tracks on the primary tracks and the slide elements 26 on the secondary tracks. In other words, one component of direction is afforded by sliding movement of the secondary tracks 18 along the length of the primary tracks 14; whereas, another component of direction is afforded by movement of the slide elements 26 along the length of the secondary tracks 18. In this manner, it will be seen that a point on the slide elements (e.g., any one of the clips 28), is capable of movement in all directions parallel to the backup metal plate 10. Examples of commercial refractory materials which can be applied or gunned on the support structure of this invention is described in Modern Refractory Practice, copyright 1961 by Harbison-Walker Refractories Company, pages 161 through 166.

With reference to FIG. 5, there is shown an alternate design for the refractory support. The support includes a support wall 100, to which is secured relatively short primary tracks 102. Secondary tracks 104 of similar size and shape as the primary tracks are arranged to overlie the primary tracks, as in FIG. 2. The secondary tracks 104 are supported on the primary tracks 102, for thermally expansive sliding movement along said tracks by C-shaped slide elements 106 of a length greater than the primary tracks, to afford secondary protection for the tracks 102. The backs of the slide elements 106 are secured to the secondary tracks, as was stated previously with respect to the original design. C- shaped slide elements 108 are also provided for slidable engagement with secondary tracks 104, as in FIG. 2. The slide elements 108 are, preferably, of the same length as slide elements 106, and are of greater length than the secondary tracks 104.

Rigidly attached to side elements 108 are cover plates -1 10 containing clips 112, with dimensions preferably equal to the length of slide elements 106 and 108. The cover plates afford primary protection for the tracks 102 and 104, to insure expansive movement in all directions. Fluid impervious films 114 are disposed on plates 1 10, so that the clips 112 perforate the films. The films 114 effectively prevent the monolithic material from flowing under plates 110, to obstruct the expansive motion of the Wall support and further prevent the monolithic material from becoming rigidly attached to wall 100. Metal laths 116 are attached to plates 110, and are secured thereto by clips 1 12. The monolithic wall 118 is then applied in any desired manner; such as, gunning and troweling.

This tmodified design of the wall support will obviate the necessity for the track guards 34, shown in FIG. 2. The lengths of slide elements 106 and 108 will be governed by the maximum anticipated expansion of the metal wall 100, with reference to the monolithic wall 118.

Another modification of the design to facilitate expansive movement in all directions would be to suitably deploy wheels, rollers, or bearings, in the same relative cooperating sequence as the tracks and slide elements.

It is recognized that a problem exists when a ceiling section meets a wall section or when two walls meet at an angle since it is anticipated that the main supporting wall, being a metal wall, will expand when exposed to heat. The monolithic wall is difiicult to attach to the corners. It is suggested that heavy woven asbestos cloth, or glass cloth or the like, could be used to make the corner transitions. If gas pressures are such that the flue gasses would be forced through the woven fabric to come in contact with the metal walls, it is suggested that a back pressure of fresh air could be employed in the annular space between the monolithic wall and the metal wall, that would equalize the pressure of the hot gases in the chamber. In this manner, passage of the flue gases into the annular space to corrode the metal wall would be prevented.

Thus, it will be seen that by this invention there is provided an extremely effective apparatus, by which a monolithic coating or lining may be attached to a metal support without danger of damage to the refractory, due to differences in coeflicients of thermal expansion between the refractory and metal backup plate. Moreover, various modifications and adaptations of the connecting apparatus of this invention may be employed, Without departing from the true spirit and scope of this invention. Accordingly, it is to be distinctly understood that the above description is illustrative only, not limiting, and that the true scope of the present invention is to be determined by reference to the accompanying claims.

We claim:

1. Apparatus for connecting a monolithic refractory lining to a support wall having a different coeflicient of thermal expansion comprising: a plurality of generally parallel primary tracks mountable on said support wall, a plurality of generally parallel secondary tracks overlying said primary tracks and extending in directions to intersect the directions of said primary tracks, means supporting said secondary tracks on said primary tracks for expansive sliding movement in the direction of said primary tracks, track guard elements overlying said primary tracks and extending between said secondary tracks to separate the primary tracks from the refractory lining, and means engaging the refractory lining, said last mentioned means including elements slidably engaging said secondary tracks to be expansively movable along the length thereof.

2. The apparatus recited in claim 1 including further, a cover plate overlying said primary and secondary tracks to protect the tracks from the refractory lining.

3. The apparatus recited in claim 1 wherein said lastmentioned means includes further, an open grille adapted to be embedded in the refractory lining and fixedly secured to said slide elements.

4. The apparatus recited in claim 3 including a fluid impervious film between said tracks and said grillework.

5. Apparatus for supporting a monolithic coating of refractory material on a metal support Wall comprising a plurality of primary tracks secured to the metal wall and extending in generally parallel directions, a plurality of generally parallel secondary tracks overlying said primary tracks and extending in a direction substantially perpendicular to said primary tracks, said secondary tracks being of generally T-shaped cross-section to present a pair of laterally projecting flanges spaced from said primary tracks, slide element means supporting said secondary tracks on said primary tracks for expansive sliding movement in the direction of said primary tracks, slide elements of generally C-shaped cross-section slidably engaging said secondary tracks, each of the slide elements substantially covering the outer faces of the primary and secondary tracks presented in the direction of the refractory coating, cover plates rigidly secured to said last mentioned slide elements, a grillework of metal lath adapted to be embedded in the refractory coating, means on said cove-r plates for engaging said metal lath and a sheet of fluid impervious material overlying said cover plates and said tracks.

6. Apparatus for supporting a monolithic coating of refractory material on a metal support wall comprising a plurality of generally parallel primary tracks secured to the metal wall, a plurality of generally parallel sec ondary tracks overlying said primary tracks and extending in a direction substantially perpendicular to said primary tracks, said secondary tracks being of generally T-shaped cross-section to present a pair of laterally projecting flanges spaced from said primary tracks, slide element means supporting said secondary tracks on said primary tracks for expansive sliding movement in the direction of said primary tracks, slide elements of generally C-shaped cross-section slidably engaging said secondary tracks, each of the slide elements substantially covering the outer faces of the primary and secondary tracks presented in the direction of the refractory coating.

References Cited by the Examiner UNITED STATES PATENTS 2,040,534 5/1936 Roth 52--346 X 2,656,902 10/1953 Gotshall 52--573 X 2,673,459 3/1954 Overh-alse 52432 X 2,847,849 8/1958 Reintjes 52-479 2,949,981 8/1960 Ferrell 52-573 X RICHARD W. COOKE, JR., Primary Examiner.

FRANK L. ABBOTT, Examiner.

R. S. VERMUT, Assistant Examiner. 

1. APPARATUS FOR CONNECTING A MONOLITHIC REFRACTORY LINING TO A SUPPORT WALL HAVING A DIFFERENT COEFFICIENT OF THERMAL EXPANSION COMPRISING: A PLURRALITY OF GENERALLY PARALLEL PRIMARY TRACKS MOUNTABLE ON SAID SUPPORT WALL, A PLURALITY OF GENERALLY PARALLEL SECONDARY TRACKS OVERLYING SAID PRIMARY TRACKS AND EXTENDING IN DIRECTIONS TO INTERSECT THE DIRECTIONS OF SAID PRIMARY TRACKS, MEANS SUPPORTING SAID SECONDARY TRACKS ON SAID PRIMARY TRACKS FOR EXPANSIVE SLIDING MOVEMENT IN THE DIRECTION OF SAID PRIMARY TRACKS, TRACK GUARD ELEMENTS OVERLYING SAID PRIMARY TRACKS AND EXTENDING BETWEEN SAID SECONDARY TRACKS TO SEPARATE THE PRIMARY TRACKS FROM THE REFRACTORY LINING, AND MEANS ENGAGING THE REFRACTORY LINING, SAID LAST MENTIONED MEANS INCLUDING ELEMENTS SLIDABLY ENGAGING 